U.S. patent application number 10/787654 was filed with the patent office on 2004-09-02 for recoil starter of force accumulation type.
Invention is credited to Kihara, Taro, Tsunoda, Shuhei.
Application Number | 20040168668 10/787654 |
Document ID | / |
Family ID | 32905810 |
Filed Date | 2004-09-02 |
United States Patent
Application |
20040168668 |
Kind Code |
A1 |
Tsunoda, Shuhei ; et
al. |
September 2, 2004 |
RECOIL STARTER OF FORCE ACCUMULATION TYPE
Abstract
A recoil starter is disclosed which enables a rotational force
to be accumulated in accumulating means with a light pulling force
and the accumulated rotational force to start an engine through
simple operations. A cam wheel is rotated using a rotational force
which has been accumulated in the accumulating means by pulling a
recoil rope. Retention means is operable to restrain or permit the
rotation of the cam wheel. Release means operates the retention
means to restrain the rotation of the cam wheel by pulling a handle
attached to the recoil rope, and operates the retention means to
permit the rotation of the cam wheel by fixing the handle in a main
casing.
Inventors: |
Tsunoda, Shuhei; (Tokyo,
JP) ; Kihara, Taro; (Tokyo, JP) |
Correspondence
Address: |
SNELL & WILMER LLP
1920 MAIN STREET
SUITE 1200
IRVINE
CA
92614-7230
US
|
Family ID: |
32905810 |
Appl. No.: |
10/787654 |
Filed: |
February 26, 2004 |
Current U.S.
Class: |
123/185.14 ;
123/185.3 |
Current CPC
Class: |
F02N 3/02 20130101; F02N
5/02 20130101 |
Class at
Publication: |
123/185.14 ;
123/185.3 |
International
Class: |
F02N 003/02; F02N
005/02 |
Foreign Application Data
Date |
Code |
Application Number |
Feb 28, 2003 |
JP |
2003-54539 |
Claims
What is claimed is:
1. A recoil starter of a force accumulation type comprising: a main
casing provided on an inner side thereof with a reel shaft; a rope
reel having a recoil rope wound therearound and rotatably supported
around the reel shaft; a recoil spiral spring for rotatingly urging
the rope reel in a direction in which the recoil rope is taken up;
a cam wheel, rotatably supported around the reel shaft, for
transmitting rotation to a rotating member coupled to an engine;
accumulating means, disposed between the rope reel and the cam
wheel, for accumulating a rotational force due to the rotation of
the rope reel, the cam wheel being rotated by the accumulated
rotational force so that the rotating member is rotated via a
transmission mechanism; retention means operable to restrain or
permit the rotation of the cam wheel; and release means which
operates the retention means to restrain the rotation of the cam
wheel by pulling a handle attached to an end of the recoil rope, to
thereby allow the accumulating means to accumulate a rotational
force, and which operates the retention means to permit the
rotation of the cam wheel by fixing the handle in the main casing,
to thereby allow the rotational force accumulated in the
accumulating means to be released to the cam wheel.
2. The recoil starter according to claim 1, wherein the retention
means comprises a stopper lever engageable with lock pawls formed
on the cam wheel to restrain the rotation of the cam wheel, and
wherein the release means comprises a release lever that is
operated by pulling the handle so that the release lever engages
with the stopper lever to restrain the movement of the stopper
lever.
3. The recoil starter according to claim 2, wherein the release
lever includes an operating piece of which an end is disposed to
correspond to a support portion for receiving the handle, which
support portion is slidably disposed on the main casing, and
wherein the release lever is operated via the operating piece due
to the handle being received in the support portion and fixed in
the main casing, so that the stopper lever is operated to permit
the rotation of the cam wheel.
4. The recoil starter according to claim 1, further comprising a
reduction mechanism in the form of a planetary gear mechanism,
interposed between the rope reel and the accumulating means, for
transmitting the rotation of the rope reel to the accumulating
means at a reduced speed, to thereby reduce the pulling force of
the recoil rope.
5. The recoil starter according to claim 2, further comprising a
reduction mechanism in the form of a planetary gear mechanism,
interposed between the rope reel and the accumulating means, for
transmitting the rotation of the rope reel to the accumulating
means at a reduced speed, to thereby reduce the pulling force of
the recoil rope.
6. The recoil starter according to claim 3, further comprising a
reduction mechanism in the form of a planetary gear mechanism,
interposed between the rope reel and the accumulating means, for
transmitting the rotation of the rope reel to the accumulating
means at a reduced speed, to thereby reduce the pulling force of
the recoil rope.
7. The recoil starter according to claim 1, wherein the
transmission mechanism comprises a centrifugal ratchet mechanism
which includes cam pawls formed on an outer peripheral surface of
the cam wheel and centrifugal ratchets that are rotatably disposed
on the rotating member disposed at the engine so as to
disengageably engage with the cam pawls.
8. The recoil starter according to claim 2, wherein the
transmission mechanism comprises a centrifugal ratchet mechanism
which includes cam pawls formed on an outer peripheral surface of
the cam wheel and centrifugal ratchets that are rotatably disposed
on the rotating member disposed at the engine so as to
disengageably engage with the cam pawls.
9. The recoil starter according to claim 3, wherein the
transmission mechanism comprises a centrifugal ratchet mechanism
which includes cam pawls formed on an outer peripheral surface of
the cam wheel and centrifugal ratchets that are rotatably disposed
on the rotating member disposed at the engine so as to
disengageably engage with the cam pawls.
10. The recoil starter according to claim 6, wherein the
transmission mechanism comprises a centrifugal ratchet mechanism
which includes cam pawls formed on an outer peripheral surface of
the cam wheel and centrifugal ratchets that are rotatably disposed
on the rotating member disposed at the engine so as to
disengageably engage with the cam pawls.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a recoil starter of a force
accumulation type having rotational force accumulating means such
as a spiral spring for accumulating a rotational force of a rope
reel which is rotated by pulling a recoil rope, wherein the
rotational force accumulated in the accumulating means is
transmitted to a crankshaft of an engine to start the engine.
[0003] 2. Description of the Related Art
[0004] A recoil starter of a force accumulation type is known in
the art in which a rotational force is accumulated in accumulating
means such as a spiral spring by pulling a recoil rope wound around
a recoil reel. When the rotational force accumulated in the
accumulating means exceeds the load of an engine, the rotational
force accumulated in the accumulating means is released and
transmitted to a crankshaft of the engine to start the engine. In
such a conventional recoil starter of a force accumulation type,
when the load of the engine at the engine starting is small, the
rotational force accumulated in the accumulating means is released
to the engine to rotate the crankshaft before a rotational force
sufficient to start the engine has been accumulated. That is, a
rotational speed sufficient for starting the engine cannot be
obtained and the engine cannot be started with the accumulated
rotational force. Therefore, it has been necessary to pull the
recoil rope in association with the rotational force accumulated in
the accumulating means.
[0005] A recoil starter of a force accumulation type has already
been proposed in which a rotation of a cam resulting from
accumulating means is obstructed until a sufficient rotational
force has been accumulated in the accumulating means, wherein in
this state, a recoil rope is pulled several times to rotate a rope
reel several times so that a sufficient rotational force is
accumulated in the accumulating means, and thereafter, the
rotational force accumulated in the accumulating means is rapidly
released to a crankshaft of the engine by operating an operational
lever, so that the engine is started only by the rotational force
accumulated in the accumulating means (see, e.g., Japanese Patent
Application Laid-Open Publication No. 7-174061).
[0006] This conventional recoil starter is constructed so that a
rotational force is accumulated in a spiral spring serving as the
accumulating means by taking up the spiral spring around an outer
peripheral surface of a drum that transmits rotation to the
crankshaft of the engine via a centrifugal clutch mechanism. The
drum is rotated in a direction opposite to an engine starting
direction via a planetary reduction mechanism and a drive shaft
rotated by pulling the rope while the drum is engaged with a lock
mechanism that obstructs rotation in the engine starting direction,
so that the rotational force is accumulated in the spiral spring.
Thereafter, the locked state of the lock mechanism is released by
operating release means which is separately formed, so that the
drum is rapidly rotated by the rotational force accumulated in the
spiral spring, whereby the crankshaft is rotated to start the
engine.
[0007] In this conventional recoil starter, it is necessary to
return the recoil rope and further operate the release means after
the rotational force has been accumulated in the accumulating means
by pulling the recoil rope. In a case where the accumulated
rotational force is insufficient and the recoil rope is again
pulled, it becomes necessary to again grip a handle of the recoil
rope. In addition, since the rotational force remains accumulated
in the accumulating means when the recoil starter is left as it
stands after pulling the recoil rope, the engine is in danger of
starting contrary to one's intention if one's hand accidentally
touches the release means.
SUMMARY OF THE INVENTION
[0008] The present invention has been made in order to solve the
problems of the above-described conventional recoil starters.
Accordingly, it is an object of the present invention to provide a
recoil starter which enables a rotational force to be accumulated
in accumulating means by pulling a recoil rope with a light pulling
force, wherein the rotational force accumulated in the accumulating
means is released to an engine to start the engine by fixing a
handle for pulling the recoil rope in a main casing.
[0009] In order to attain the above object, according to the
present invention, there is provided a recoil starter of a force
accumulation type. The recoil starter comprises: a main casing
provided on an inner side thereof with a reel shaft; a rope reel
having a recoil rope wound therearound and rotatably supported
around the reel shaft; a recoil spiral spring for rotatingly urging
the rope reel in a direction in which the recoil rope is taken up;
a cam wheel, rotatably supported around the reel shaft, for
transmitting rotation to a rotating member coupled to an engine;
accumulating means, disposed between the rope reel and the cam
wheel, for accumulating a rotational force due to the rotation of
the rope reel, the cam wheel being rotated by the accumulated
rotational force so that the rotating member is rotated via a
transmission mechanism; retention means operable to restrain or
permit the rotation of the cam wheel; and release means which
operates the retention means to restrain the rotation of the cam
wheel by pulling a handle attached to an end of the recoil rope, to
thereby allow the accumulating means to accumulate a rotational
force, and which operates the retention means to permit the
rotation of the cam wheel by fixing the handle in the main casing,
to thereby allow the rotational force accumulated in the
accumulating means to be released to the cam wheel.
[0010] In a preferred embodiment of the invention, the retention
means comprises a stopper lever engageable with lock pawls formed
on the cam wheel to restrain the rotation of the cam wheel, and the
release means comprises a release lever that is operated by pulling
the handle so that the release lever engages with the stopper lever
to restrain the movement of the stopper lever.
[0011] In a preferred embodiment of the invention, the release
lever includes an operating piece of which an end is disposed to
correspond to a support portion for receiving the handle, which
support portion is slidably disposed on the main casing, and the
release lever is operated via the operating piece due to the handle
being received in the support portion and fixed in the main casing,
so that the stopper lever is operated to permit the rotation of the
cam wheel.
[0012] In a preferred embodiment of the invention, the recoil
starter further comprises a reduction mechanism in the form of a
planetary gear mechanism, interposed between the rope reel and the
accumulating means, for transmitting the rotation of the rope reel
to the accumulating means at a reduced speed, to thereby reduce the
pulling force of the recoil rope.
[0013] In a preferred embodiment of the invention, the transmission
mechanism comprises a centrifugal ratchet mechanism which includes
cam pawls formed on an outer peripheral surface of the cam wheel
and centrifugal ratchets that are rotatably disposed on the
rotating member disposed at the engine so as to disengageably
engage with the cam pawls.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] The above and other objects, aspects, features and
advantages of the present invention will become more apparent from
the following detailed description when taken in conjunction with
the accompanying drawings, in which:
[0015] FIG. 1 is a sectional side elevation view showing a recoil
starter of a force accumulation type according to an embodiment of
the invention;
[0016] FIG. 2 is a front view of the recoil starter of a force
accumulation type shown in FIG. 1;
[0017] FIG. 3 is a rear view of the recoil starter of a force
accumulation type shown in FIG. 1;
[0018] FIG. 4 is a cross-sectional view taken along line 4-4 of
FIG. 1;
[0019] FIG. 5 is a cross-sectional view taken along line 5-5 of
FIG. 1;
[0020] FIG. 6 is an explanatory diagram showing a state, prior to
operation, of the recoil starter of a force accumulation type;
and
[0021] FIG. 7 is an explanatory diagram showing a state, during
operation, of the recoil starter of a force accumulation type.
DETAILED DESCRIPTION OF THE INVENTION
[0022] An embodiment of the invention will be described below with
reference to the drawings. As shown in FIG. 1, a recoil starter of
a force accumulation type according to the invention is configured
so that, by pulling a handle 2 disposed so as to project outward
from a main casing 1 housing main components, a recoil rope 3 fixed
to the handle 2 is pulled to cause a rope reel 4 having the recoil
rope 3 wound therearound to rotate. The rope reel 4 is rotatably
mounted to a reel shaft 5 which is attached to part of the main
casing 1 so as to coaxially face a crankshaft C of an engine. A
drum portion 4a is formed at an outer periphery of the rope reel 4,
and the recoil rope 3 is wound around the drum portion 4a of the
rope reel 4 while an end thereof is fixed to the rope reel 4. As
shown in FIG. 2, the other end of the recoil rope 3 is pulled
outward from the main casing 1 through an opening 6 formed in the
main casing 1 and attached to the handle 2. By pulling the handle
2, the recoil rope 3 is pulled out and the rope reel 4 is rotated
around the reel shaft 5.
[0023] A recoil spiral spring 7 is disposed between a side surface
of the rope reel 4 and an inner wall surface of the main casing 1.
The recoil spiral spring 7 is adapted to rotate, in the opposite
direction, the rope reel 4 which has been rotated in an engine
starting direction by pulling the recoil rope 3, to thereby rewind
the recoil rope 3 pulled out from the drum portion 4a of the rope
reel 4 around the rope reel 4. An inner peripheral end of the
recoil spiral spring 7 is fixed to the reel shaft 5, and an outer
peripheral end of the recoil spiral spring 7 is fixed to the rope
reel 4. When the recoil rope 3 is pulled and the rope reel 4 is
rotated, a rotational force is accumulated in the recoil spiral
spring 7. By releasing the recoil rope 3 or loosening the pulling
force on the recoil rope 3, the rope reel 4 is rotated in the
opposite direction by the rotational force accumulated in the
recoil spiral spring 7, whereby the recoil rope 3 pulled out to the
outside of the main casing 1 is rewound around the rope reel 4.
[0024] A spring case 9, which accommodates accumulating means 8
that accumulates a rotational force of the rope reel 3, is
rotatably supported on the reel shaft 5. The rotation of the rope
reel 4 in the engine starting direction is transmitted to the
spring case 9 via a reduction mechanism 10. The reduction mechanism
10 is configured by a planetary gear mechanism comprising a sun
gear 11, which is rotatably attached to the reel shaft 5, and
planet gears 13, which are disposed between an outer periphery of
the sun gear 11 and an inner periphery of a ring gear or internal
gear 12 formed in the main casing 1 and which are rotatably
supported on the spring case 9. The rope reel 4 is coupled to the
sun gear 11 of the reduction mechanism 10 via a one-way clutch 14.
The one-way clutch 14 is configured so that when the recoil rope 3
is pulled to rotate the rope reel 4 in the engine starting
direction, the rotation of the rope reel 4 is transmitted to the
sun gear 11, and when the rope reel 4 is rotated in the opposite
direction by the recoil spiral spring 7, the rotation is not
transmitted to the sun gear 11. Due to the reduction mechanism 10,
the spring case 9 is rotated by a light pulling force of the recoil
rope 3.
[0025] Moreover, a cam wheel 15 that transmits the rotational force
accumulated in the accumulating means 8 is rotatably attached to
the reel shaft 5. The cam wheel 15 is held by a screw 16 screwed
into an end of the reel shaft 5 so that the sun gear 11, the spring
case 9 and the cam wheel 15 do not come off the reel shaft 5. The
accumulating means 8 is configured by a spirally wound spiral
spring. The spiral spring 8 is received inside a recess formed in a
side wall of the spring case 9. An outer peripheral end of the
spiral spring 8 is fixed to the spring case 9, and an inner
peripheral end of the spiral spring 8 is engaged with the cam wheel
15. Thus, the rotational force is accumulated in the spiral spring
8 by the rotation of the rope reel 4 in the engine starting
direction, and the cam wheel 15 is rotated in the engine starting
direction by the rotational force accumulated in the spiral spring
8.
[0026] In a state where the main casing 1 is attached to the
engine, the cam wheel 15 is disposed so as to face a rotating
member 17 attached to the crankshaft C of the engine. A
transmission mechanism 18 for transmitting the rotation of the cam
wheel 15 in the engine starting direction to the rotating member 17
is provided between the cam wheel 15 and the rotating member 17.
The transmission mechanism 18 in the illustrated embodiment is
configured by a plurality of cam pawls 15a formed on an outer
peripheral surface of the cam wheel 15 along a circumferential
direction thereof and centrifugal ratchets 18a disposed on the
rotating member 17 that are caused to engage with and disengage
from the cam pawls 15a by centrifugal force. When the cam wheel 15
is rotated in the engine starting direction, the centrifugal
ratchets 18a engage with the cam pawls 15a to cause the rotating
member 17 to rotate in the engine starting direction. When the
engine starts and the rotating member 17 is rotated via the
crankshaft C, the centrifugal ratchets 18a are each turned by
centrifugal force counter to an urging force of a spring and
disengage from the cam pawls 15a so that the rotation from the
engine is not transmitted to the recoil starter.
[0027] A plurality of lock pawls 19 facing a direction opposite to
the engine starting direction are formed along a circumferential
direction on an outer peripheral surface of the spring case 9.
Ratchets 20 are rotatably disposed in the main casing 1 so as to
engage with the lock pawls 19, whereby rotation of the spring case
9 in the opposite direction is obstructed. The ratchets 20 are
constantly and elastically urged in a direction in which they
engage with the lock pawls 19. Thus, when the rope reel 4 is
rotated in the engine starting direction, the spring case 9 is
rotated via the reduction mechanism 10 in the engine starting
direction to wind up the spiral spring 8, so that the rotational
force of the rope reel 4 is accumulated in the spiral spring 8
while the spring case 9 is prevented from being rotated in the
direction opposite to the engine starting direction by the
rotational force accumulated in the spiral spring 8.
[0028] Retention means 22 is provided between the cam wheel 15 and
the main casing 1 so that when a rotational force is accumulated in
the spiral spring 8 by pulling the recoil rope 3, the retention
means 22 prevents the cam wheel 15 from being rotated in the engine
starting direction by the rotational force accumulated in the
spiral spring 8. The retention means 22 is configured by lock pawls
23 formed on the outer peripheral surface of the cam wheel 15 and a
stopper lever 24 that is pivotally disposed in the main casing 1
and engages with one of the lock pawls 23 to restrain the rotation
of the cam wheel 15. A stopper piece 25 formed on the stopper lever
24 engages with an engagement surface of one of the lock pawls 23
that faces the engine starting direction, whereby the rotation of
the cam wheel 15 in the engine starting direction is obstructed.
The stopper lever 24 is pivotally moved between a first position
where the stopper piece 25 thereof engages with one of the lock
pawls 23 and a second position where the stopper piece 25 thereof
is separated from the lock pawls 23. The stopper lever 24 is urged
by a spring 26 towards the first position at which the stopper
piece 25 thereof engages with one of the lock pawls 23, so that the
stopper lever 24 is ordinarily disposed at the first position where
the stopper piece 25 thereof engages with one of the lock pawls
23.
[0029] The stopper lever 24 includes an operational piece 27 which
is integrally formed with the stopper piece 25. Release means 28,
which engages with an end of the operational piece 27 to retain the
stopper lever 24 at the first position where the stopper piece 25
of the stopper lever 24 engages with one of the lock pawls 23 and
which disengages from the end of the operational piece 27 to allow
the stopper piece 25 of the stopper lever 24 to abut against the
lock pawls 23 so that the stopper lever 24 pivots, is provided in
the main casing 1. The release means 28 is configured by a release
lever 29 that is pivotally supported on the main casing 1. An
engagement protrusion 30 that is engageable with the operational
piece 27 of the stopper lever 24 and an operating piece 31 that
extends towards a portion where the handle 2 attached to the end of
the recoil rope 3 is housed in the main casing 1 are integrally
formed on the release lever 29. The release lever 29 is pivotally
urged by a spring 32 in a direction in which the engagement
protrusion 30 engages with the operational piece 27 of the stopper
lever 24, so that the release lever 29 retains the stopper lever 24
at the first position where the stopper piece 25 of the stopper
lever 24 engages with-one of the lock pawls 23 of the cam wheel
15.
[0030] As shown in FIG. 2, the recoil rope 3 wound around the rope
reel 4 is pulled to the outside of the main casing 1 through the
opening 6 formed in the main casing 1. The recoil rope 3 is passed
through a guide sleeve 34 retained at a support portion 33 formed
on the main casing 1, and the handle 2 is attached to the end of
the recoil rope 3. The guide sleeve 34 includes an upper cup-shaped
portion 34a that is so formed that a lower portion of the handle 2
can be received therein and a lower cylindrical portion 34b that is
slidably supported by the support portion 33 of the main casing 1.
In a state where the recoil starter is not being operated, the
recoil rope 3 is wound around the drum portion 4a of the rope reel
4 and drawn inside the main casing 1 by the rotational force of the
recoil spiral spring 7 while a lower surface of the cup-shaped
portion 34a of the guide sleeve 34 is caused to abut against an
upper surface of the support portion 33 in a state where the lower
portion of the handle 2 is received in the cup-shaped portion 34a
of the guide sleeve 34.
[0031] An end portion of the operating piece 31 of the release
lever 29 is interposed between the lower surface of the cup-shaped
portion 34a of the guide sleeve 34 and the support portion 33
formed on the main casing 1. In a state where the recoil starter is
not being operated, the recoil rope 3 undergoes a winding force
from the rope reel 4 so that the operating piece 31 is pushed
against the upper surface of the support portion 33 via the guide
sleeve 34, wherein the engagement protrusion 30 of the release
lever 29 is separated from the operational piece 27 of the stopper
lever 24 to maintain the stopper lever 24 in a state where the cam
wheel 15 can be rotated. When the recoil rope 3 is pulled out from
the rope reel 4 via the handle 2 in order to start the engine, the
handle 2 is separated from the guide sleeve 34 to permit the guide
sleeve 34 to slide, and the operating piece 31 pushes the guide
sleeve 34 up due to the pivotal urging force of the spring 32
acting on the release lever 29, so that the engagement protrusion
30 of the release lever 29 is pivotally moved to the position where
the engagement protrusion 30 engages with the operational piece 27
of the stopper lever 24. As a result, in a state where the stopper
piece 25 of the stopper lever 24 is disposed in the position where
the stopper piece 25 engages with one of the lock pawls 23 of the
cam wheel 15, the rotation of the stopper lever 24 is obstructed,
whereby the rotation of the cam wheel 15 is obstructed by the
stopper piece 25.
[0032] Next, the operation of the recoil starter of a force
accumulation type according to the illustrated embodiment will be
described. Prior to a starting operation of the engine, as shown in
FIG. 6, the rope reel 4 has been rotated in the direction opposite
to the engine starting direction by the action of the recoil spiral
spring 7, and the recoil rope 3 is wound around the rope reel 4,
wherein the recoil rope 3 is drawn inside the main casing 1 by the
urging force of the recoil spiral spring 7, and the guide sleeve 34
is pushed towards the support portion 33 of the main casing 1 while
the lower portion of the handle 2 is received inside the cup-shaped
portion. 34a of the guide sleeve 34. The operating piece 31 of the
release lever 29 is operated by the guide sleeve 34 to pivot so
that the operating piece 31 pushes against the upper surface of the
support portion 33, and the engagement protrusion 30 of the release
lever 29 is pivotally moved to the position where the engagement
protrusion 30 is separated from the operational piece 27 of the
stopper lever 24, whereby the operational piece 27 of the stopper
lever 24 is allowed to be pivotally moved and the cam wheel 15 can
be rotated.
[0033] As shown in FIG. 7, by gripping the handle 2 and pulling out
the recoil rope 3 in order to start the engine, the handle 2 is
separated from the support portion 33 of the main casing 1, to
thereby permit the guide sleeve 34 to slide. The operating piece 31
of the release lever 29 that has been pushed against the support
portion 33 via the guide sleeve 34 is operated, by the urging force
of the spring 32 pivotally urging the release level 29, to pivot
and push up the guide sleeve 34, so that the engagement protrusion
30 is moved by pivoting of the release lever 29 to the position
where the engagement protrusion 30 engages with the operational
piece 27 of the stopper lever 24. The stopper piece 25 of the
stopper lever 24 is disposed on a rotational locus of the lock
pawls 23 of the cam wheel 15 by the action of the spring 26 while
the engagement protrusion 30 of the release lever 29 engages with
the operational piece 27 of the stopper lever 24 to obstruct the
rotation of the stopper lever 24, whereby the stopper piece 25 of
the stopper lever 24 cannot leave the rotational locus of the lock
pawls 23 of the cam wheel 15, resulting in the rotation of the cam
wheel 15 being obstructed.
[0034] When the rope reel 4 is rotated in the engine starting
direction by pulling the handle 2, the spring case 9 is rotated via
the reduction mechanism 10 constituted by the planetary gear
mechanism and the rotational force is transmitted to the cam wheel
15 via the spiral spring 8. However, the rotation of the cam wheel
15 is obstructed by the lock pawls 23 of the cam wheel 15 engaging
with the stopper piece 25, whereby the spring case 9 is rotated and
the rotational force is accumulated in the spiral spring 8. When
the pulling force of the handle 2 is loosened, the rope reel 4 is
rotated in the opposite direction by the rotational force
accumulated in the recoil spiral spring 7 and the recoil rope 3 is
rewound around the rope reel 4. When the rope reel 4 is rotated in
the opposite direction, the rotation of the rope reel 4 is not
transmitted to the sun gear 11 of the reduction mechanism 10 due to
the one-way clutch 14. Although the spring case 9 will be caused to
rotate in the opposite direction by the rotational force
accumulated in the spiral spring 8, the ratchets 20 engage with the
lock pawls 19 formed on the outer periphery of the spring case 9,
so that the rotation of the spring case 9 in the opposite direction
is obstructed. In this manner, the rotational force is accumulated
in the spiral spring 8 by repeatedly pulling the recoil rope 3.
Since the rotation of the cam wheel 15 is obstructed during this
time by the stopper lever 24 that is the retention means 22, the
rotational force is not transmitted to the rotating member 17
coupled to the crankshaft C of the engine.
[0035] When the handle 2 is received in the cup-shaped portion 34a
of the guide sleeve 34 and released after the rotational force has
been sufficiently accumulated in the spiral spring 8 by repeatedly
pulling the recoil rope 3, as shown in FIG. 6, the rope reel 4 is
rotated in the opposite direction by the rotational force
accumulated in the recoil spiral spring 7 so that the recoil rope 3
is rewound around the rope reel 4, whereby the guide sleeve 34
causes the operating piece 31 of the release lever 29 to pivot due
to the pulling-in force of the recoil rope 3, and the engagement
protrusion 30 is operated to pivot so that the engagement
protrusion 30 separates from the operational piece 27 of the
stopper lever 24. As a result, the stopper lever 24 is permitted to
pivotally move so that the rotational force accumulated in the
spiral spring 8 is released to the cam wheel 15, and the rotation
of the cam wheel 15 is transmitted to the rotating member 17 via
the transmission mechanism 18, with the result that the crankshaft
C is rapidly rotated to start the engine. When the engine starts
and the rotating member 17 is rotated via the crankshaft C, the
centrifugal ratchets 18a of the transmission mechanism 18 are
rotationally moved outward by the action of centrifugal force to
disengage from the cam pawls 7a of the cam wheel 15, whereby the
rotation of the engine is not transmitted to the cam wheel 15.
[0036] As described above, the recoil starter of a force
accumulation type according to the invention is constructed so that
the rotational force is accumulated in the accumulating means by
the rotation of the rope reel, and the cam wheel is rotated by the
accumulated rotational force so that the rotating member is rotated
via the transmission mechanism, wherein the recoil starter is
provided with the retention means operable to restrain or permit
the rotation of the cam wheel, and the release means which operates
the retention means to restrain the rotation of the cam wheel by
pulling the handle attached to the recoil rope and which operates
the retention means to permit the rotation of the cam wheel by
fixing the handle in the main casing. According to such
construction, regulation of the rotation of the cam wheel is
automatically carried out while the handle is pulled in order to
start the engine, and the rotation of the cam wheel can be allowed
by returning the handle to the received position. Therefore, a
special operation to retain or release the rotation of the cam
wheel is not needed, and the engine starting operation can be
easily conducted. In addition, since the cam wheel is placed in a
freely rotatable state other than during the engine starting
operation, the spiral spring is not left in a state where the
rotational force is accumulated in the spiral spring, so that
accidents resulting from a mistaken operation can be prevented.
[0037] In one embodiment of the invention, the retention means
comprises the stopper lever engageable with the lock pawls formed
on the cam wheel to restrain the rotation of the cam wheel, and the
release means comprises the release lever that is operated by
pulling the handle so that the release lever engages with the
stopper lever to restrain the movement of the stopper lever. Thus,
it is possible to retain or release the rotation of the cam wheel
with a simple configuration resulting from two levers, resulting in
the manufacturing cost of the recoil starter of a force
accumulation type being prevented from increasing.
[0038] In one embodiment of the invention, the release means is
provided on the release lever with the operating piece of which the
end is disposed to correspond to the support portion for receiving
the handle, which support portion is disposed on the main casing,
wherein the release lever is operated via the operating piece due
to the handle being received in the support portion, so that the
stopper lever is operated to permit the rotation of the cam wheel.
Therefore, such a simple construction enables the rotation of the
cam wheel to be retained or permitted in conjunction with the
operations of pulling the handle or fixing the handle in the
support portion, resulting in the manufacturing cost of the recoil
starter of a force accumulation type being prevented from
increasing.
[0039] In one embodiment of the invention, the recoil starter of a
force accumulation type further includes the reduction mechanism in
the form of a planetary gear mechanism, interposed between the rope
reel and the accumulating means, for transmitting the rotation of
the rope reel to the accumulating means at a reduced speed.
Therefore, it becomes possible to cause the accumulating means,
which comprises the spiral spring of a strength sufficient to start
the engine, to accumulate the rotational force with a small amount
of labor even when the force with which the recoil rope is pulled
is small while the handle is gripped, resulting in the engine
starting operation being easily carried out.
[0040] In one embodiment of the invention, the transmission
mechanism for transmitting the rotational force from the cam wheel
to the rotating member comprises the centrifugal ratchet mechanism
which includes the cam pawls formed on the outer peripheral surface
of the cam wheel and the centrifugal ratchets that are rotatably
disposed on the rotating member disposed at the engine so as to
disengageably engage with the cam pawls. Therefore, the rotation of
the cam wheel is reliably transmitted to the rotating member, and
the rotational force can be prevented from being transmitted from
the engine to the cam wheel after the engine has started.
[0041] While the illustrative and presently preferred embodiment of
the present invention has been described in detail herein, it is to
be understood that the inventive concepts may be otherwise
variously embodied and employed and that the appended claims are
intended to be construed to include such variations except insofar
as limited by the prior art.
* * * * *